Tire Size - 12R vs 295/80R

[markpj23]

Hate to start another tire thread but I'm having a problem in the Phoenix area finding replacement 295/80R 22.5 tires. Coach came with GY G670s from the factory. The GY G670s and Michelins are available, but I was hoping to find a Toyo, Continental or Hankook based upon the numerous threads here.

Dealer says not many manufacturers are making the 295s. They offered up a Toyo 12R 22.5 but my web search tells me it's about 1/2 inch narrower, etc. Not sure what other dimensions may be different - when you get into revolutions per mile and affect upon speedometer etc I descend into confusion.

Is there a benefit in going to the 12R tire size (other than availability)? Is there a reason NOT to go to the 12R from the 295/80R 22.5 tire size?

Thanks in advance,

[Twomed]

I put 12R's on the rear, plenty of carrying capacity. They are about 1 inch taller, deeper tread and ride/handle great. Firestone FS560 little over $600 each mounted balanced and 10% sales tax in TN (OUCH)...but I was desperate to get the crappy Goodyears off. Have run 315 FS 400's on the front for over a year like Ivylog...and love them.

I tried to get the Michelin 295 CaoachX with Monaco Intnl pricing...even with the Michelin contact rep they could only locate 26 tires in all of the states, they wanted to ship in one here, one there, no date guarantee. I was of course concerned a bit about replacing one on the road. The Firestones were 4 weeks old/new, have run them for about three months and 4k miles...very happy.

Speedo is 2.5 miles slow according to gps. Engine rpm is down 100 at 63 where I try to run most of the time and of course mileage is up a bit. That is with the 400 ISL.

PS>>>I do not know if you have clearance on the front tires for taller tires. There are several different configs on the pass side font air bag. I have seen different clearances on some coaches, something to do with step wells it appears. Also not sure I would want a narrower tire on the fronts. ???

[Dynasty_09]

Unless I'm mistaken, the 12R is a truck tire. So it would not have the same resistance to sun and weather. If you do a lot of mileage, no problems, if you park most of the time, they might not last as long...

[walt2137]

Originally Posted by Cayman09

Unless I'm mistaken, the 12R is a truck tire. So it would not have the same resistance to sun and weather. If you do a lot of mileage, no problems, if you park most of the time, they might not last as long...

Michel where did you hear that, the only difference i know is the sidewall ply, I have the 11R on our coach now and didnt see any difference in ride and had the Toyo tires (truck tires) on our old coach and could not tell the difference in the ride from the Goodyear RV tire and about all of us RVers never wear them out we just have to replace at about 7 yrs. My tires are in good enough shape after 7 yrs that I sell them to Loggers for their trailers, win win for both of us.

Mark on the 12R at 100 psi Dual rate is 5895 and Single 6405, the 295/80 at 100 psi is D 5805 and S 6405 they are pretty close in weight and one advantage to the 12R is if you do have a tire problem they are easily replaced at about any truck tire center, not so with the RV tires they can be pretty hard to come by.

[Twomed]

Ran 275/70/22.5 Toyos on the Safari for 130K...TRUCK TIRES...never covered...zero problems. Keep drinking the "Rv tires are special Kool Aid".

I guess if they were so good all the truckers would be buying them up...

RV...Marine...Aviation...$$$$$ ha...ha!!

[moisheh]

Our Bluebird uses 12R tires and they are not always available in other than Michelin and GY. RV tires are not special other than some UV protection. The GY670's are RV specific yet are the worst tire on the market. You have to be careful when buying truck tires as there are many different types. Some are trailer specific, some are steering only while others are drive axle only. Some are desgned for city PU&D. Others are best suited for gravel trucks. Line haul tires are usually OK for RV use. Most mfrs. have a website that shows which lines are suitable for RV's.

[lonestarace]

Best we can tell, Toyo only makes 1 all-position 12R size 22.5 tire, the M111Z. Its 0.2" narrower, 11.6" vs 11.8" and over an inch taller, 42.6" vs 41.3", than a Michelin XZA2 Energy 295/80-22.5. The Toyo is designed for local service, which means they have stronger sidewalls and will tolerate a lot of curb hoppin. This Toyo is a tall tire and wheel well clearance may be a problem.

We hope this helps?

[deSanford]

FWIW let me say that a trucker puts on over 100,000 miles a year and probably replaces his tires every two years. I believe there is a reason why there is an RV tire, and that probably has to do with the materials used to make each. As an example if there was too much of one type of material ( nylon?) the tires would have a flat spot from sitting in one place too long etc.

[CoCoDave]

Originally Posted by markpj23

Hate to start another tire thread but I'm having a problem in the Phoenix area finding replacement 295/80R 22.5 tires. Coach came with GY G670s from the factory. The GY G670s and Michelins are available, but I was hoping to find a Toyo, Continental or Hankook based upon the numerous threads here.

Dealer says not many manufacturers are making the 295s. They offered up a Toyo 12R 22.5 but my web search tells me it's about 1/2 inch narrower, etc. Not sure what other dimensions may be different - when you get into revolutions per mile and affect upon speedometer etc I descend into confusion.

Is there a benefit in going to the 12R tire size (other than availability)? Is there a reason NOT to go to the 12R from the 295/80R 22.5 tire size?

Thanks in advance,

Mark,

Like you I got confused when looking at 11R and 12R tires as a replacement for our 295x80Rx22.5 tires. There is an abundance of data to be compared and I did not want to make tire selection my new career. Bridgestone has their R250 tire in 295x80Rx22.5 size and it's widely available, at least out here. They are made in Nashville, TN, and most Bridgestone/Firestone dealers that handle larger tires can get them quickly.

Last September I paid $658.71 apiece, all in - out the door. That included mounting, spin balancing, stems, all applicable taxes, old tire disposal fees, with the same date code, etc, etc.

FWIW

[moisheh]

There are only 2 so called RV specific tires available. The Michelin XRV and the GY G670's. Both are problematic tires. The GY is the absolute worst RV tire ever built. The XRV has (or had) a bad reputation but I wonder if the problems were due to a bad batch or owner neglect. Neither of those tires are available in a wide range of sizes. I doubt they have 12R's. Most major tire companies do have tires that are truck tires but also are suitable for an RV. The XZE and XZA are not only recommended for RV's by Michelin they are OEM on most high end units. There is a wide selection of tires that would be suitable for an RV. DO NOT take the word of your tire dealer. Go to the website for the tire you like and see what the mfr. recommends. Call them if necessary. BTW: I see Monaco and Thor using Continentals on some new units.

[pipedream2]

I may be wrong here and haven't checked the size chart but a 295 80r tire should be 295 mm tread and 80% bead height with which is 11.6 inches wide ......would the 12r be 3/8in wider not narrower than the tire you are taking off..The GY 295 mm tread is 307mm at the side wall......don't know about the 12r sidewall dimension bit will be more than 12in
I am I wrong here or what

[Twomed]

OK guys this looks like it is starting to evolve into a rvnet type discussion.

The OP asked specific questions about 12Rs. I went through all the tire charts from all the mfrs. plus asked and observed commercial bus users that run through our parking areas in Yellowstone all summer tire questions. Watching their abuse (non owners) and good habits (owner operators) I concluded that a good brand steer/all position truck tire was fine. That along with our great dissatisfaction of only safely getting 60K out of GY670s that would not wear right on the fronts even with a Josam alignment made "rv tires" a definite no purchase decision. They ran fine on age basis on the rear and tag only.

Several people on this board have pretty extensive commercial use tire experience and are running truck tires. Michelin has a whole list of "truck tires" on their FMCA and Monaco Intl pricing plan to choose from. Very few folks here run the miles necessary to wear out treads so buying a shallower tread "rv tire" that is supposed to have better UV properties makes no sense whatsoever to me..JMHO UV promise is from the same company that claims there is no such thing as rivering I might add.

Buy what you like...but my New Year's resolution is to only answer questions I have experience with...not espouse opinions based on internet legend. I hope some others will join me in that so these boards become more helpful.

Happy New Year...

[D Barber]

Hi,
In Phoenix go to Roberts tire. They sell Continental HSR2 SA. THey come in a 295/80/22.5 size and are promoted by Roberts as a bus/rv tire.
Have 4 on rears and with 8k on them they are OK so far.
Don

[D Barber]

Hi, additional info

7800 lb single, 6900 dual load rating on the Conti,s